Individual ergonomists can make significant strategic contributions to the design of systems, in addition to the traditional “knobs and buttons” work. Ergonomists should be aware of the ways in which “the human element” or its neglect can derail systems. Ergonomists may be able to contribute knowledge or at least awareness of human abilities and weaknesses to the processes of planning, design and implementation of interfaces at virtually all stages. Planning is often the weakest point in the production of a human-computer interface. It is easy to accept ill-defined specifications in the hope that they can be clarified “in the light of events”. Task analysis is a necessarily time-consuming but essential part of the design process. Ergonomists should be familiar with, at least, Hierarchical Task Analysis. Most ergonomists acquire a practical knowledge of experimental design and methodology during their training. Electronic engineers generally are unaware of the need for testing, or the procedures for evaluating potential interfaces in relevant conditions.